Boeing booked a new firm order for 10 large wide-body 777-300ERs from Chinese carrier Cathay Pacific at the Asian Aerospace show in Hong Kong on Wednesday.

Separately, the plane maker identified Russian-flag carrier Aeroflot as the customer behind an order for eight 777s booked last month.

The two orders are together worth an estimated $2.7 billion after discounts.

The Cathay order is worth $2.8 billion at list prices, but the airline said the jets “will be acquired at a considerable discount, as is the usual practice in such transactions.” Based on market price data from aircraft-valuation firm Avitas, the true price is about $1.5 billion.

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At the same time, Cathay said it will take 15 smaller A330 wide-body jets from Airbus and will lease an additional two Airbus A350-900s from airplane lessor International Lease Finance Corp.

Last September, Cathay ordered 30 A350-900s and six Boeing 777-300ERs. The additional order will bring its total 777 fleet to 46.

Cathay also has a large air-cargo operation and has 10 of the freighter version of the new 747-8 jumbo jets on order.

One of the world’s largest airlines, Cathay has been headquartered in Hong Kong since its founding in 1946. Despite the transfer of that city’s administration from British to Chinese rule in 1997, it operates relatively independently of the Chinese government.

Cathay CEO Tony Tyler said in a statement the airline plans to retire its four-engine wide-body aircraft — Boeing 747-400s and Airbus A340-300s — before the end of the decade, replacing them with the more fuel-efficient 777s and A350s.

The Aeroflot order is for six 365-seat 777-300ERs and two 300-seat 777-200ERs and is worth $2.2 billion at list prices. After standard discounts based on Avitas valuations, the real value is about $1.2 billion.

Vitaly Saveliev, Aeroflot’s general director, said the planes will be used as part of the airline’s planned growth in anticipation of the 2014 Sochi Olympic Winter Games and the 2018 FIFA World Cup.

Russia is an important 777 supplier for the Boeing. VSMPO, a subsidiary of Rostechnologii State Corporation, manufactures large titanium forgings for landing gears, wings and pylon of the airplane.